Seat cushion length extender with sensor

ABSTRACT

Seats and methods for controlling a seat are described. A position of the user&#39;s leg is sensed relative to the position of the front of the seat. A determination is made as to if the position of the user&#39;s leg from a front of the seat is greater than a gap minimum. If the gap is greater than the gap minimum, a cushion length extender portion of the seat is moved until the sensed position is less than or equal to the gap minimum. In an example, the remainder of seat base is held in a fixed position within the vehicle environment. The gap minimum can be with the cushion length extender portion in slight contact with the user&#39;s leg. The sensor can be at a front face of seat. The sensor can be on the cushion length extender portion of the seat.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.14/614,892, filed Feb. 5, 2015, now U.S. Pat. No. 9,499,072 issued Nov.22, 2016, which claims the benefit of U.S. Provisional Application No.61/940,668, filed Feb. 17, 2014; which is hereby incorporated herein byreference in its entirety and made part of the present U.S. UtilityPatent Application for all purposes.

TECHNICAL FIELD

The following relates to a system and method for controlling themovement of a seat in a vehicle and, more specifically, to controllingmovement of a seat cushion support portion of the seat.

BACKGROUND

Automotive vehicles often include electrically powered systems forcontrol of seat movement or seat positions. Such systems may provide formovement or adjustment of various seat portions in a variety ofdirections, which can include moving a seat bottom forward, rearward,upward and/or downward, as well as forward or rearward reclining ortilting of a seat back. Such controls and positioning of the seat mayprovide improved ergonomics to the user.

Exemplary vehicle seat control systems are shown in U.S. PatentApplication Publication No. 2006/0208549 titled “Automotive Seat WithControl System” and International Application Publication No. WO2008/024306 titled “Object Detection System And Method For MovingVehicle Seat.” Exemplary sensors for use in vehicle seats are shown inU.S. Patent Application No. 2011/0147051 titled “Capacitive SwitchSensors On Decorative In-Mold Films Background;” International PatentApplication Publication No. WO 2009/103653 titled “Flexible Seat SensorProduct,” and U.S. Patent Application No. 2009/224584A titled “ActiveMaterial Actuated Seat Base Extender.”

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a seat with cushion length extender.

FIG. 2 shows a schematic view of a seat with cushion length extender.

FIG. 3 shows a schematic view of a seat with cushion length extender.

FIG. 4 is a cross-sectional diagram of a sensor assembly in an exemplaryvehicular environment for use in embodiments of the system and methodfor controlling movement of a vehicle seat of the present disclosure.

FIG. 5 is a simplified block diagram of an embodiment of the sensorsystem.

FIG. 6 is a simplified block diagram of an embodiment of the sensor

FIG. 7 shows a method of operating the seat.

DETAILED DESCRIPTION

Detailed embodiments of the present invention are disclosed herein;however, it is to be understood that the disclosed embodiments aremerely exemplary of the invention that may be embodied in various andalternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Referring now to FIG. 1, a vehicular environment is shown for oneembodiment of a vehicle seat system 10 of the present disclosure with auser sitting on the seat system. A seat 11 can include a seat base 13and a seat back 14. A sensor 12 can be positioned in a seat base 13 andmay be used to slow, limit, stop, reverse or otherwise control seat basemovement or movement of a portion of the seat base automatically withoutintervention by a user. In an example, the seat base 13 may support theuser's upper leg, for example, thigh, by controlling position of thecushion length extender 15 of the seat base 13. In an example, thecushion length extender 15 is part of the seat base 13 and is configuredto move relative to the remainder of the seat base 13. The positioningof the cushion length extender 15 depends on the length of the user'sleg and the size of the seat base 13. That is, the seat base 13 may notfully support a user's leg for all sizes of users. The sensor 12, whichcould be capacitive, RF based or temperature based, may be used todetect the position of the user, and, more specifically, the user's legwith the user being seated in the seat 11. The sensor 12 may also detectthe user being seated in the seat 10 and then activate to detect theposition of the user and, e.g., at least one of the user's legs. Theposition is sensed as distance “d” in FIG. 1. In an example, thedistance may be set to a gap distance that is adjacent the user's legbut not touching the lower part of the user's leg that extendsdownwardly toward the vehicle floor or pedal. The sensor may also detectthe position of the seat relative to the vehicle environment, e.g., asdescribed in U.S. patent application Ser. No. 13/834,378, to set a limiton the amount of travel for the seat cushion extender 15, for example,when the seat is moved to its forward most position with the vehiclecabin. The cushion length extender 15 is shown in a retracted positionin FIG. 1. The retracted position may be desirable for entry to andexiting from the vehicle or for users who have shorter legs. Theretracted position of the cushion length extender 15 results in the seatbase having a shorter seat base length than an extended position of thecushion length extender that increases the seat base length. It will beappreciated that the seat system 10 will include a stand (not shown)that fixes the seat 11 to the vehicle, e.g., the floor of the vehicle.

The cushion length extender 15 includes an actuator 17 that provideslinear motion to the cushion length extender 15 in response to receivedelectrical control signals, which may be based on signals from thesensor 12. The actuator 17 is shown positioned in the seat base 13 inthis example. The actuator 17 can be fixed relative to the seat base 13,a frame of the seat or an internal seat support. The front edge 16 ofthe cushion length extender 15 is essentially positioned at the frontedge of the remainder of the seat base 13. In an example, the front edge16 also defines the front most surface of the seat base 13. The sensor12 can be positioned in the cushion length extender 15 adjacent itsfront edge 16 such that when a user (e.g., a driver) is in the vehicleand on the seat 11 the sensor can sense the user's leg with the leg infront of the edge 16.

FIG. 2 shows the cushion length extender 15 of the seat 11 in theextended position after sensing the position of the user by the sensor12. Based on sensed location of the user, the cushion length extender 15moves from the retracted position (FIG. 1) to the extended position(FIG. 2). The extended position of the cushion length extender providesgreater support to the upper leg (i.e., at least part of the thigh) ofthe user. The actuator 17 is shown positioned below in the seat base 13in this example and can be, in an example, mounted to the seat stand.The cushion length extender 15 moves the location of the front edge ofthe seat forward, i.e., left in FIGS. 1 and 2, in the direction the useris facing. The top surface of the cushion length extender 15 contactsthe underside of the user's upper leg, e.g., thigh, and supports theuser's leg. Currently positioning the cushion length extender 15relative to the person's leg may increase the comfort of the person. Asshown in FIG. 2, the front edge 16 of cushion length extender 15 maycontact the back of the user's knee and the lower leg just below theknee. In some examples, the front edge may stop just short of contactingthe user's leg and leave a gap therebetween, which can be sensed bysensor 12 and controlled based on the sensed information from the sensor12.

FIG. 3 shows the cushion length extender 15 of the seat 11 in anotherextended position after sensing by the sensor 12 of the position of theuser. In the FIG. 3 position, the cushion length extender 15 hasundesirably moved too far forward (left in FIG. 3) and its front edge 16has contacted the back of the user's lower leg, e.g., behind the knee oralong the calf. If the extender 15 moves beyond a slight contact againstthe user's leg, the extender 15 may strongly press on the leg and mayundesirably inhibit movement, decrease comfort of the user or evenextend the user's leg. The sensor 12 can sense the distance between thefront of the cushion length extender and the user's lower leg and stopforward movement of cushion length extender before contact with theuser's leg. In some use cases, the user may adjust their position andcome into contact with the front edge 16. In this case, the sensor 12can sense this change in user position and adjust the cushion lengthextender 15 from the contacting position (FIG. 3) to a correct positionwith a gap that is larger than a minimum distance and smaller than amaximum distance. Alternatively, sensor 12 may comprise a contactpressure sensor that allows a slight pressure between the cushion lengthextender 15 and the user's leg. In this example, the gap between thecushion length extender and the user's leg just closed. The closed gapmaintains this slight pressure through retraction of the cushion lengthextender 15 if the user changes position such that the contact pressureincreases.

FIG. 4 shows a cross-sectional diagram of a sensor assembly 70 in anexemplary vehicular environment for use with the seating system 10(FIGS. 1-3). As seen therein, a structure 72 of the seat base 13 caninclude body 74 and a trim 76, which may have an outside surface (A) andsubstrate (B). One or more sensors 12, which may be capacitive sensors,light sensors, RF sensors, microwave sensors or temperature sensors, canbe part of a flexible circuit 78 (which may have a thickness ofapproximately 0.002 inches) positioned between the body 74 and the trim76 of the structure 72. The sensor assembly 70 may also include aprinted circuit board 80 having other electrical circuitry 82 and/or aconnector or electrical wire harness interface 84. The sensor 12 canextend around the front edge of the seat cushion. In an example, thesensor 12 extends from a top surface of the seat to about halfway downthe front of the seat. In an example, the sensors 12 are placed at thefront of the seat assembly.

FIG. 5 shows a simplified block diagram of an embodiment of the seatingsystem 10 and associated method(s) for controlling movement of a vehicleseat 11. As seen therein, the sensor assembly 70 may be provided incommunication with a control unit 86, which may be provided incommunication with a seat movement controller 88, thereby enablingoperation of the system 10 and associated method for slowing, limiting,stopping, reversing or otherwise controlling seat movement as describedherein, e.g., travel of the cushion length extender 15. The control unit86 can include circuitry such as discrete components, switches,Application-Specific Integrated Circuits (ASICs), programmable logicarrays, and memory devices or other computing devices.

The control unit 86 can also act as a learning algorithm that can allowthe user to position the cushion length extender at a desired location.The control unit 86 can receive a selection indication from the userthat the current position of the cushion length extender is the desiredlocation. The control unit 86 can receive the indication through aswitch located in the seat or through vehicle input means, such as atouchscreen, voice commands, data entry switches in the vehicle, keyfobs and the like. In another example, the user moves the cushion lengthextender to a desired location multiple times and the control unit 86associates that position with the user and stores that repeated locationas the desired location of the cushion length extender. The control unit86 can also process the data associated with the user's positioning ofthe cushion length extender to arrive at a predicted position of thecushion length extender 15 for that user. In an example, the controlunit 86 can average the manual positioning of the cushion lengthextender 15 over a few, e.g., greater than two, positioning actions bythe user. The control unit can also use other statistics, e.g., a medianvalue or a greatest frequency, to select the position of the cushionlength extender. The control unit 86 can use the sensor to determine theposition of cushion length extender 15 or use the state (e.g., position)of the actuator 17 to determine the position of the cushion lengthextender 15. It will be appreciated that the control unit 86 in theseexamples learns the position of the cushion length extender over usetime by the user.

FIG. 6 is a simplified schematic of a sensor 12 for use in embodimentsof the seating system 10 and related method(s) for controlling movementof a vehicle seat 11. The sensor 12 can be capacitive in nature and mayinclude capacitors C₀ 64 and C₁ 66, as well as one or more circuitries38 to execute electrical operations. The circuitry can include ASICs,processors, logic gate arrays, switches, memories and combinationsthereof. A conductive object (such as a body part of a user 40, driveror occupant) positioned closer to capacitor C₁ 66 than capacitor C₀ 64increases the capacitance of C₁ 66 more than the capacitance ofcapacitor C₀ 64. Thus, the change in the capacitance of C₁ 66 is afunction of the distance of an object 40 from the capacitor C₁ 66, aswell as the area of the pad of capacitor C₁ 66 coupled to the object 40,which provides an indication of the size of the sensed object 40 inorder to help prevent false indications of proximity. The sensor 12 maybe configured such that a sufficient increase in the capacitance of C₁66 relative to that of capacitor C₀ 64 detects a switch activation,thereby indicating the presence of an object 40 which may be used toslow, limit, stop, reverse or otherwise control the position of thecushion length extender, i.e., set travel, movement or position.Filtering may also be employed to require a time lapse before such adetected change in capacitance will be accepted for purposes of switchactivation.

FIG. 7 shows a flowchart of a method 700 for controlling a seat, e.g.,seat 10. At 701, it is determined whether the sensors are active, i.e.,“on.” The sensor(s) can be “off” based on the state of the vehicle,e.g., the vehicle is off, there is no power to the sensors, or the userhas turned off this feature. At 703, if the sensor(s) are “off”, thenthe seat does not adjust and the cushion length extender remains in itsdefault state, which may be the retracted position. At 705, if thesensor(s) is on, the system determines if there is a gap between thefront edge of the seat and the leg of the user. If the gap is greaterthan a predetermined gap, then the system determines that the leg is notsupported by the cushion length extender. The predetermined gap can beset by the user as an input to the vehicle. The predetermined gap canalternatively be set by the vehicle manufacturer. At 707, the cushionlength extender moves forward, either a distance as determined by thesystem or begins movement and then returns to step 705. If at 708, it isdetermined that the gap distance from the front edge of the seat to theuser's leg is less than the predetermined gap, then the systemdetermines that the leg is closer to the front edge of the seat thandesired and the cushion length extender move retracts toward the seatand away from the user's leg. Once the gap distance is reached, step709, the cushion length extender stays in its position.

In an example method, the seating system can include contact pressuresensors located in the seat cushion extender. The seat cushion extendercan operate to provide a preset level of pressure to the back of theuser's lower leg. The user can select pressure settings selectable frompre-set levels (for example, high, med, low). In another example, theuser sets the pressure during a learning phase, wherein the sensor withthe cushion length extender moves towards the user's leg and appliespressure. Once the user's desired pressure is reached, the user haltsthe movement of the cushion length extender and the seating systemstores this pressure value as the desired or set pressure for movementof the cushion length extender. In operation after the learning phase,once the selected pressure is reached, the sensor and the cushion lengthextender stop moving forward. For example, when the pressure matches theoccupant's desired setting or distribution pattern is achieved, theextender halts for the remaining of this drive cycle unless anotheradjustment is requested.

As described herein, the position of the thigh support of a seat, e.g.,for a vehicle, can be adjusted to better support the user. In anexample, a sensor uses capacitive sensing to send a signal toautomatically control an actuator that can extend the front portion ofthe cushion until it senses the occupant (ex: occupant's calf). In anexample, a sensor uses pressure sensing to determine the position of thefront portion of the seat cushion, e.g., the cushion length extender,relative to the user's leg. In other examples, the system can haveadjustable sensing, e.g., based on selectable pre-set settings based onpressure sensing such as high, low, medium or corresponding values. Inanother example, the seating system provides adjustable sensing with acontinuous spectrum adjustable pressure settings using a known pressurespot whereat the user's leg contacts the seat extender. In an example,it may be desirable to return cushion length extender to the full inposition when the vehicle is turned off to allow easy exit and reentry.

As described herein the sensor can be located in the seat base cushionlength extender. Positioning the sensor at the cushion length extendermay allow the use of either a capacitive sensor in an example or apressure sensor in an example. When using a pressure sensor, the userselects a pressure setting. The sensor allows the cushion lengthextender to move towards the user's leg and to apply a pressure to theuser's leg. When the pressure matches the occupant's desired setting ordistribution pattern is achieved, the extender halts for the remainingportion of this drive cycle unless another adjustment is requested.Other types of sensors can also be used to control the movement of thecushion length extender. Examples include radio frequency sensor,microwave sensor, temperature sensor and infrared sensor. However, theuse of a light sensor will require the emitter to extend through thematerial of the seat or the seat material to be transparent to the lightor other signal sent by the sensor.

The presently described seat systems and methods are equally applicableto front seats and rear seats. The front seats can be bucket seats,e.g., seats built for a single person. The rear seats can be bucketseats or seat assemblies that support more than one person. In the caseof a seat assembly, for example, a bench type seating arrangement. In anexample, the sensor will interact only with the person seating in analigned position with the cushion length extender.

The cushion length extender, in an example, can have a width that issubstantially the same width and the rest of the seat base such thatwhen the cushion length extender moves the width of the seat base seemsessentially uniform to the user. In another example, the cushion lengthextender is narrower than the remainder of the seat base.

The presently described examples can offer an innovative feature ofself-adjusting upper leg support for a user. This may increase thecomfort level of the user and increase the satisfaction level of vehicleas experienced by the user. The user may be the occupant of the seat,the owner/operator of the vehicle or other people. Self-adjusting caninclude, but is not limited to, the user turning on this feature viavehicle controls or a mobile device. The user can also select theminimum gap distance from their leg to the front of the seat base. Theseating system may also turn off if a user is not seated on the seat.This can be done with a pressure sensor or other weight sensor in theseating system. The seating system sensing the position of the user'sleg, e.g., the leg nearest the seat front edge. The seating system cancontinuously sense the position of the leg and also continuously adjustthe cushion length extender position. There can be some minimum changein the gap before the cushion length extender adjusts as the sensor mayhave a greater resolution of distance than the user would enjoy changesin the position of the cushion length extender.

The present application makes reference to co-pending U.S. patentapplication Ser. No. 13/834,378, which is hereby incorporated byreference for any purpose, including combining the present explicitdisclosure with the disclosure of application Ser. No. 13/834,378.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

We claim:
 1. A method for controlling a seat comprising: sensing aposition of a user's leg relative to a front face of a seat to determinea sensed gap; determining if the position of the user's leg from a frontof the seat is greater than a predetermined gap; if the sensed gap isgreater than the predetermined gap, moving a cushion length extenderportion of the seat until the sensed position is less than or equal tothe predetermined gap.
 2. The method of claim 1, further comprisingholding the seat in a fixed position within a vehicle environment. 3.The method of claim 1, wherein sensing comprises sensing includingcapacitively sensing a position of the user's leg.
 4. The method ofclaim 1, wherein sensing comprises sensing using at least one of athermal sensor, a light sensor, a radio frequency sensor, a microwavesensor or combinations thereof to sense the position of the user's leg.5. The method of claim 1, wherein the predetermined gap is with thecushion length extender portion in slight contact with the user's leg.6. The method of claim 5, wherein sensing comprises sensing using apressure sensor at a front face of the cushion length extender.
 7. Themethod of claim 1, wherein sensing comprises sensing using a sensor onthe cushion length extender portion.
 8. The method of claim 1, whereinsensing a position of a user's leg includes again sensing the positionwhen the user moves in the seat.
 9. A method for controlling a seatcomprising: electronically sensing a position of a user's leg relativeto a front face of a seat to determine a sensed gap; determining if theposition of the user's leg from a front of the seat is greater than apredetermined gap; if the sensed gap is greater than the predeterminedgap, moving, while holding the seat in a fixed position within a vehicleenvironment, a cushion length extender portion of the seat until thesensed position is less than or equal to the predetermined gap.
 10. Themethod of claim 9, wherein electronically sensing comprises sensingincluding capacitively sensing a position of the user's leg.
 11. Themethod of claim 9, wherein electronically sensing comprises at least oneof radio frequency sensing, a microwave sensing, or combinations thereofto sense the position of the user's leg.
 12. The method of claim 9,wherein moving the cushion length extender portion of the seat includesmoving the cushion length extender portion in slight contact with theuser's leg and then retracting the cushion length extender portion. 13.The method of claim 9, further comprising initially positioning thecushion length extender portion at a start position based on priorpositioning of the cushion length extender portion.
 14. The method ofclaim 13, wherein positioning the cushion length extender portionincludes using a statistical average of prior seat positions and cushionlength extender portion positions to determine the start position.
 15. Amethod for controlling a seat comprising: storing a set gap between afront face of a seat and a leg of a seated person; sensing a position ofthe seated person's leg relative to the front face of the seat todetermine a sensed gap; determining if the position of the user's legfrom the front face of the seat is greater than a set gap; if the sensedgap is greater than the set gap, moving a cushion length extenderportion of the seat until the sensed position is less than or equal tothe set gap.
 16. The method of claim 15, wherein storing the set gapincludes moving the cushion length extender portion until a pressure issensed and then retracting the cushion length extender portion a setdistance.
 17. The method of claim 15, further comprising retracting thecushion length extender to shorten the seat base when the sensedposition is less than the set distance.
 18. The method of claim 15,wherein the set distance is with the cushion length extender adjacentand free from contact with the leg of the seated person.
 19. The methodof claim 15, further comprising initially positioning the cushion lengthextender portion at a start position based on prior positioning of thecushion length extender portion.
 20. The method of claim 15, whereinstoring the set gap includes moving the cushion length extender portionuntil a pressure is sensed and then retracting the cushion lengthextender portion a set distance; wherein the set distance is with thecushion length extender adjacent and free from contact with the leg ofthe seated person; further comprising moving the cushion length extenderto shorten a base of the seat when the sensed position is less than theset distance; and further comprising initially positioning the cushionlength extender portion at a start position based on prior positioningof the cushion length extender portion, with the start position being acalculated position based on prior seat positions and cushion lengthextender portion positions.